Endless tread machine



Dec. 8, 1936.

B. H. FLYNN ENDLEss TREAD MACHINE 3 Sheets-Sheet 2 Filed Feb. 17, 1936 El-TL Dec. s, 1936. B, H, FLYN 2,063,238 4 ENDLESS TREAD MACHINE Filed Feb. 17, 1936 3 Sheets-Sheet I5 r/r//r fr r r/////////// Patented Dec. 8, 1936 UNITED STATES PATENT oFFlcE 2,063,238 ENDLEss TREAD MACHINE Benjamin H. Flynn, Alexandria, La. Application February 17, 193s, serial No. 64,392 4 claims. (o1. sos- 4) The invention relates to endless tread supporting means for mobile machines, and it is intended primarily for heavy machines used in highway construction, for instance, subgraders. It

has heretofore been the practice to provide such machines with flanged wheelsI to travel upon the usual side forms used in the construction of concrete highways, but due to the Weight of the machines, the wheels often severely injure said side forms, making frequent and expensive replacements necessary. One of the foremost objectsv of the present invention is to provide novel endless tread supporting means for the heavy machines to so distribute the weight upon the side forms as to prevent injury thereto.

A further object is to provide a new and improved endless tread supporting means (whether operating upon side forms or rails or upon the ground) in which the weight of the machine is supported upon Ythe entire lengths of the lower reaches of the endless tread chains and in which the chains and tracks are engaged in a novel manner.

A-still further object is to provide an improved construction in which no sprockets are necessary for mounting endless tread chains which support one end of the machine, and in which the sprockets necessary for driving endless chains which support the other end of the machine, are the only sprockets required in mounting these chains.

, Still lanother object is to provide a novel construction in which the endless tread chains may be conveniently formed by merely fastening tread plates to the links of conventional heavy-duty roller-type sprocket chains, said tread plates being flanged if intended to travel upon side` forms or rails.

. With the foregoing and minor objects in view, the invention resides in the novel subject matter hereinafter described and claimed, description being accomplished by reference to the accompanying drawings.

Fig. 1 is a side elevation partly broken away and in section showing a subgrader improved in accordance with the present invention. Fig. 2 is an enlarged detail horizontal sectional view on line 2 2 of Fig. 1.

Fig. 3 is a detail vertical longitudinal sectional view on line 3 3 of Fig. 2.

Fig. 4 is a detail vertical transverse sectional view on line 4 4 of Fig. 1.

Fig. 5 is an enlarged detail horizontal sectional view on line 5 5 oi Fig. 1.

Fig. 6 is an enlarged transverse sectional View on line 6 6 of Fig. 1.

Fig. 'I isa vertical sectional view on line 1 1 of Fig. 1.

Fig. 8 is a detail horizontal sectional view on line 8 8 of Fig. 7.

While the construction illustrated in the drawings may be considered as` preferred and will be rather specically described, it is to be understood that within the scope of the invention as claimed, numerous variations may be made. Moreover, while a subgrader has been shown embodying the invention, it` will be understood that the latter is not restricted to use with any particular kind of machine.

The subgrader G includes a. motor-driven cutting drum D provided with appropriate means A whereby its ends may be independently or simultaneously adjusted between the side forms F upon which the machine travels.

. rIv'wo endless tread chains IU are provided for the front of the machine and two similar chains IEL are provided for the rear thereof, and provision is made whereby the weight of the machine is supported lupon the entire lengths of the lower reaches of these chains and whereby the front of` the machine may be raised or lowered with respect to the chains and the side forms` without disturbing the distribution of weight upon the lower reaches of said chains.

The endless tread chains I0 and IIJa are preferably formed by riveting or bolting flat tread platesII to lugs I2 now commonly provided on the side links I3 of conventional heavy-duty roller-type sprocket chains. Such chains, in addition to the side links I3 include central links I4, the rollers I being mounted upon transverse axes between said side and central links, this being Vexplained in View of the fact that the links and rollers are associated in a novel way with certain track construction to be hereinafter described. Y

Themeans for supporting the front end of the machine upon the lower reaches of the chains I0, includes tracks I6 circumscribed by said chains Ill and engaging .all of the rollers thereof, together with suitable jacks II connected with said tracks and .the frame of the machine for vertically adjusting the front end of the latter. The means for ysupporting the rear end of the machine upon the lower reaches of the rear chains Illa, includes driven sprockets I8 and tracks I9. While there is one track I6, one track I9, one jack I'I and one sprocket I8 at each side of the machine, these parts have been shown for one side only to avoid duplication of illustration. The track. I6 is provided with a continuous edge 20 preferably straight along its upper and lower portions and curved at the front and rear ends of said track, these curved portions occupying the bight portions of the chain I0. For purposes of adjustment to compensate for wear, one end 2| of the track I6 may be separate from the remainder of said track and adjustably connected to it by any preferred means 22. To the central portion of the track I6, the arched lower end 23 of the jack I'I is pivoted as shown at 24, the pivot preferably passing through a sleeve 25 which extends through said track and is welded to the latter. The upper portion of the jack I1, connected with the frame of the machine G is preferably constructed as seen in Fig. '7. A vertical screw 26 is welded or otherwise secured to the arched portion 23, theupper end of this screw having threaded engagement with a sleeve 21 which is rotatably mounted on the frame of the machine as shown at 28, this sleeve being provided with a lock nut 21a. The portion of the screw 26 below the sleeve 21 is preferably provided with a surrounding tube 29 welded or otherwise secured thereto and resting upon the arched portion 23 to which it may also be fastened. This tube 29 is slidably received in a fixed tubular guide 30 welded or otherwise secured to the machine frame. By rotating the sleeve 2l with a wrench or the like, the front end of the machine is vertically adjusted as may be required.

'Ihe jack Il, the track I6 and the chain I0 are preferably located between inner and outer side plates 3| and 32 embodied in the construction of the machine` frame, and the sprocket 8, track I9 and chain Illa are also preferably housed between these plates. The hub 33 of the sprocket I 8 is rotatable on a stub-shaft 34 passing through suitable openings in and secured to the plates 3| and 32, said hub being provided with a driving sprocket 35 engaged by chain 36 forming a portion of appropriate driving mechanism 3l for said sprocket I8, all of this driving mechanism being housed between the plates 3| and 32.

The track I9 is of such shape and length as to engage substantially all of the rollers of the chain Illa which are not engaged by the sprocket I8, and said track is provided with radius plates 38 which are welded or otherwise secured thereto, said radius platesfhaving openings 39 through which the hub 33 of the sprocket I8 passes. A short rod or the like 40 is secured to the track I9 and passes through openings in said track and the radius plates 38, the ends of said rod or the like being received in short vertical slots 4I formed in the plates 3| and 32. Adjusting screws or the like 42 are carried by these plates and may be turned down to rest solidly upon the rod or the like 40, even when the frame of the machine is tilted by operating the jacks I4. Obviously, the frame will tilt about the shaft 34 as a pivot and during such tilting, the adjusting screws 42 will rise from the rod or the like 40 so that momentarily the track I9 imparts less of the machine weight to the tread chain I0 than, it should. As soon as the adjusting screws 42 are tightened, however, this is overcome. Before again lowering the front end of the machine, the screws 42 should of course be loosened, but after lowering to the required extent, said screws should again be snugly tightened.

When the machine is intended to be operated upon side forms or rails, the tread plates II of the chains I0 and I0a will be provided with flanges 43 to engage vertical faces of said side forms or rails, to guide the chains along the latter.

If the machine be intended to merely operate upon the ground, the flanges 43 will not be required and the tread plates II, being then subjected to greater wear, could well be of heavier construction to resist such wear.

From the foregoing, taken in connection with the accompanying drawings, it will be seen that I have provided a novel construction by which the weight of the machine is distributed over relatively large areas of the supporting surface or surfaces instead of being localized or concentrated as when using supporting wheels. Moreover, the construction is such that the entire lengths of the lower reaches of the tread chains are utilized to support the weight of the machine without placing any severe tensional strains upon said reaches, such as those which necessarily exist when uneven portions of the supporting surface thrust upwardly on portions of the chains not solidly held by contact with tracks or the like, for instance, the chain portions ordinarily traveling across gaps between front and rear sprockets and chain-engaging tracks extending between the lower portions of said sprockets, as in a number of prior endless tread machines. No sprockets whatever are required in connection with the chains I0 and only a driving sprocket is necessary in connection with each of the chains Ia, providing a structure which is less expensive and at the same time superior. The grooved tracks I6 and I9 effectively guide the chains and transmit weight thereto and the chains effectively guard said tracks to prevent pieces of rock and the like from falling and accumulating thereon.

The general construction shown and described, may be followed if desired, but within the Yscope of the invention as claimed, numerous variations may be made.

I claim:-

1. In a mobile machine supporting means, an endless tread chain having longitudinal side links, additional longitudinal links between the sides of the chain, transverse rollers between said side links and said additional links, and tread plates secured to at least some of said links; and a loadf supporting chain-guiding track having a horizontal portion resting on the rollers of the lower reach of said chain, said track having at least one curved end occupying a bight portion of the chain and engaging the rollers thereof, said track being straddled by the inner edges of said side links .and being peripherally grooved to receive the inner edges of said additional links.

2. In a mobile machine supporting means, an endless tread chain having longitudinal side links, additional longitudinal links between the sides of the chain, transverse rollers between said side links and said additional links, and tread plates secured to at least some of said links; and al loadsupporting chain-guiding track having a continuous edge engaged by the rollers of said chain, said continuous track edge being straddled by the inner edges of said side links and being peripherally grooved to receive the inner edges of said additional links.

3. In a mobile machine supporting means, 'an endless tread chain having transverse rollers, means for supporting a portion of the machine frame upon the lower reach of said chain, including a driven sprocket and a track engaging the chain rollers, said track having an uninterrupted edge of a length to simultaneously engage substantially all rollers of the chain not engaged by said sprocket; said chain having side links and additional links between the sides of the chain,

and tread plates secured to at least some of the links; the inner edges of said side links being disposed astride said track edge, said track edge being grooved to receive the inner edges of said additional links.

4. In a mobile machine supporting means, an endless tread chain comprising longitudinal side links, additional longitudinal links between the sides of the chain, transverse rollers between said side links and said additional links, and tread plates secured to at least some of the links, said rollers being of a diameter less than the width of said side and additional links, whereby the links project beyond the peripheries of the rollers for track-engaging purposes.

BENJAMIN H. F'LYNN. 

